We present a Multi-Authority Attribute-Based Encryption (ABE) system. In our system, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters. A party can simply act as an ABE authority by creating a public key and issuing private keys to different users that reflect their attributes. A user can encrypt data in terms of any boolean formula over attributes issued from any chosen set of authorities. Finally, our system does not require any central authority.
In this talk, I will present our system and discuss its proof, which employs dual system encryption techniques.
Our system uses bilinear groups of composite order, and we prove security under static assumptions in the random oracle model.
This is joint work with Brent Waters.